Most employment law isn't about protecting people from being surprised by an employer it's about setting limits to what an employer can require of an employee.

Most employment law isn't about protecting people from being surprised by an employer it's about setting limits to what an employer can require of an employee. Both parties expecting at signing that you'll only get paid for half the hours you work or that you'll be paid below the required minimums doesn't make it any more legal for the business to do that.